【摘要】 一般认为,氮肥趋于降低苜蓿产量、植被组成和缩短寿命,并刺激杂草侵入。同时,苜蓿能通过共生根瘤菌进行固N₂,故此苜蓿一般不施用N肥。但近几年来也有研究表明,N肥能提高苜蓿的产量,改善其品质,并与苜蓿根瘤数和固N₂能力有关。另外,随着除草剂的应用和发展,似乎应该重新估价N肥对苜蓿的作用。更多还原

【Abstract】 Generally,it not approved of application N fertilizer to alfalfa,since N fertilizer always tends to reduce alfalfa stands,decrease its longevity,and make way for the invasion of weeds,and the alfalfa car. fix N through the symbiotic N—fixing bacteria. However,it has also been reported that N not only increases the yield but also improves the quality of alfalfa,and it influence the number of nodules,ability of N—fixing. In addition,it should be necessary to reestimate the effect of N fertilization,along with the application and improvement of herbicide.更多还原